Performance Improvements for FDDI and CSMA/CD Protocols

The High-Performance Computing Initiative from the White House Office of Science and Technology Policy has defined 20 major challenges in science and engineering which are dependent on the solutions to a number of high-performance computing problems. One of the major areas of focus of this initiative is the development of gigabit rate networks to be used in environments such as the space station or a National Research and Educational Network (NREN). The strategy here is to use existing network designs as building blocks for achieving higher rates, with the ultimate goal being a gigabit rate network. Two strategies which contribute to achieving this goal are examined in detail.1 FDDI2 is a token ring network based on fiber optics capable of a 100 Mbps rate. Both media access (MAC) and physical layer modifications are considered. A method is presented which allows one to determine maximum utilization based on the token-holding timer settings. Simulation results show that employing the second counter-rotating ring in combination with destination removal has a multiplicative effect greater than the effect which either of the factors have individually on performance. Two 100 Mbps rings can handle loads in the range of 400 to 500 Mbps for traffic with a uniform distribution and fixed packet size. Performance is dependent on the number of nodes, improving as the number increases. A wide range of environments are examined to illustrate robustness, and a method of implementation is discussed

Recent Advances in Wireless Communications and Networks

This book focuses on the current hottest issues from the lowest layers to the upper layers of wireless communication networks and provides "real-time" research progress on these issues. The authors have made every effort to systematically organize the information on these topics to make it easily accessible to readers of any level. This book also maintains the balance between current research results and their theoretical support. In this book, a variety of novel techniques in wireless communications and networks are investigated. The authors attempt to present these topics in detail. Insightful and reader-friendly descriptions are presented to nourish readers of any level, from practicing and knowledgeable communication engineers to beginning or professional researchers. All interested readers can easily find noteworthy materials in much greater detail than in previous publications and in the references cited in these chapters

Kielikeskus tutkii 3

This edition of Kielikeskus tutkii is now the third of the series that began in 2013. It was our aim from the beginning that the journal would become a permanent fixture in the daily life of our Language Centre. This 2017 edition marks a significant development in that it has been produced in collaboration with the University of Tampere Language Centre. After the publication of our last journal in 2015, talks began with teachers from Tampere with an eye to initiating some form of collaboration. What began as informal discussion, soon progressed into serious discussion on somehow working together to create a joint journal. Concrete work began with a meeting in May 2016, when we discussed initial ideas and possible partnerships between teachers. This progressed through a number of Skype meetings and the use of a joint Moodle site. The same processes we have always used in terms of feedback and peer support worked, we found, equally well despite the distance between us. What you see today is the result of this collaboration with both articles by individual staff members and also one Turku/Tampere joint article. A lot has happened in the intervening years since the first edition, both in Turku and in Tampere. In these times of change, in Turku all language teaching has been centralized to form a new unit out of five previous institutions, whilst in Tampere work on the Tampere 3 project has continued. Despite all these changes and the uncertainty they arouse, certain things have remained constant. One of these constants has been the interest and perceived need in research within a language centre context. It is our joint mission to produce research-informed teaching and the classroom-based research that you can find in this volume relates directly to this core mission. The articles show life in the language centre through a wide-angle lens, but two common themes run through the articles: the all-pervasive use of digital technology and notions of student autonomy. The first article by Alakastari and Valkama is a comparative analysis that examines the effect of different levels of support on the writing of Bachelor’s level Swedish tests. The support could be both traditional (dictionaries) or electronic and they look at the impact of support on word choice, noun and verb usage, accuracy and other related issues. Alanen and Männikkö continue the theme of analysis of Swedish language teaching and learning, focusing on teaching development from the perspective of the assessment of video-recorded oral presentations. The aim of their article was to identify those features that contribute to a successful oral presentation at CEFR B1 and B2 level. They then discuss whether, once identified, these features could be used as assessment criteria. Gamache and Horton investigate how students use online tools to improve their writing skills in English. They also focus on how their perception of these tools can help or hinder their use of them. By elucidating students’ perceptions in this area, they hope to identify key pedagogical approaches for teachers to use in graduate classes. Hildén’s article differs from the other articles in this edition of the journal in that it is not concerned directly with language but rather looks at language centres from an administrative and historical perspective, thus providing a new dimension to the journal. Hildén examines the way in which language centres have been managed and organized since their inception and charts the significant changes that have occurred. He focuses on how the changes in the law governing universities have affected language centres both internally and also their role and standing as part of the university they belong to. Hollingsworth raises fundamental questions that all teachers face: ‘What have my students learnt? Have they learnt what I think I taught them? Is it all worthwhile? … What have they retained? Have they made any use of the materials I lovingly crafted or the feedback I spent hours writing?’ In this questionnaire-based study, Hollingsworth attempts to answer these questions and examines the role of using a European Language Portfolio and other electronic tools in the retention of learning. In her article, Who owns guided self-study? Jokinen examines the issue of ownership of learning by asking students of German what significance the self-study parts of their course had for them, how they used the freedom they were given and to what extent the self-study parts of the course served the transfer of learning ‘ownership’ from the teacher to the students. The article written by Laivo-Laakso and Tuuri is a joint Turku-Tampere production and focuses on peer feedback in a Finnish writing skills context. In particular it examines the significance of peer feedback given between students on writing courses: what kind of support has been given to students who give feedback and what kind of needs and expectations they have. They consider whether giving feedback could be a transferrable skill and what factors are involved in enabling students to benefit from these skills outside a formal classroom setting. Nelson conducted a nationwide survey across all Finnish language centres, linked to the ongoing Finelc 2digi project, examining the role that digital literacy plays both in the classroom and language centre curricula. The survey confirms that the notion of digital literacy is still an unclear concept to many language teachers and that work needs to be done to clarify it at an individual and institutional level. The article concludes with suggestions for developing digital literacy skills. In the final article, Palmer examines learner autonomy in the context of portfolio usage: students were given the freedom to choose what they included in the final portfolio of an English for Academic and Professional Skills course. Palmer refers to these as ‘mix and match’ portfolios. She reports on students’ reactions to using this kind of portfolio as opposed to the more traditional pre-given format portfolio and what impact this had on their feelings of autonomy. Finally, I would like to warmly thank all those who worked so hard to make this journal happen again. It has shown that fruitful cooperation between language centres is both possible and that obstacles created by geography can be overcome. We hope you enjoy this edition wherever you may be

Towards a Conceptual Design of an Intelligent Material Transport Based on Machine Learning and Axiomatic Design Theory

Reliable and efficient material transport is one of the basic requirements that affect productivity in sheet metal industry. This paper presents a methodology for conceptual design of intelligent material transport using mobile robot, based on axiomatic design theory, graph theory and artificial intelligence. Developed control algorithm was implemented and tested on the mobile robot system Khepera II within the laboratory model of manufacturing environment. Matlab© software package was used for manufacturing process simulation, implementation of search algorithms and neural network training. Experimental results clearly show that intelligent mobile robot can learn and predict optimal material transport flows thanks to the use of artificial neural networks. Achieved positioning error of mobile robot indicates that conceptual design approach can be used for material transport and handling tasks in intelligent manufacturing systems

The 1988 Goddard Conference on Space Applications of Artificial Intelligence

This publication comprises the papers presented at the 1988 Goddard Conference on Space Applications of Artificial Intelligence held at the NASA/Goddard Space Flight Center, Greenbelt, Maryland on May 24, 1988. The purpose of this annual conference is to provide a forum in which current research and development directed at space applications of artificial intelligence can be presented and discussed. The papers in these proceedings fall into the following areas: mission operations support, planning and scheduling; fault isolation/diagnosis; image processing and machine vision; data management; modeling and simulation; and development tools/methodologies